olor changes and 5-hydroxymethyl furfural formation in zile pekmezi during storage

Abstract

RESUMENCambios del color y formación de 5-hidroximetilfurfural durante el almacenamiento de zile pekmezi.El Zile pekmezi (pekmez duro blanco) es un alimento turco tradicional que se produce a partir del zumo del uva. El color, el sabor y el contenido en 5-hidroximetilfurfural (HMF) son los pará-metros de calidad más importantes en el Zile pekmezi. El pardeaminto es el problema más común que afecta a la calidad del pekmez.En este estudio se evalúa la cinética de formación del HMF determinándose los ordenes de reacción, las constatntes de formación y la energía de activación así como las variaciones en las diferencias de color (∆E) en Zile Pekmezi, almacenado a 55, 65 y 75 o C durante 9 dias. Los resultados indicaron que la formación de HMF y la variación del color durante el proceso termal del Zile pekmezi siguieron una cinética de orden cero. Las energìas de activación calculadas para HMF y el ∆E fueron de 158.63 kJ mol -1 y 40.04 kJ mol -1, respectivamente. PALABRAS-CLAVE:Color -Hidroximetilfurfural -PekmezZile Pekmezi. SUMMARY Color changes and 5-hydroxymethyl furfural formation in zile pekmezi during storage.Zile pekmezi (white hard pekmez) is a traditional Turkish food which is produced from grape juice. Color, flavour and 5-hydroxymethyl furfural (HMF) contents are the most important quality parameters in Zile pekmezi. Browning is the most common quality problem in pekmez.In this study, reaction orders, rate constants and activation energies were evaluated for HMF formation and color difference (∆E) variation in Zile pekmezi stored at 55, 65 and 75 o C along 9 days.The results indicated that HMF formation and ∆E variation during thermal processing of Zile pekmezi followed zero order reaction kinetics at 55, 65 and 75°C. Calculated activation energy fo r H MF a n d ∆Ewere 158.63 kJ mol -1 a nd 40 .04 kJ mol -1 , respectively. KEY-WORDS: Color -Hydroxymethylfurfural -PekmezZile Pekmezi.

Quality Kinetics and Storage Stability Studies of Ready to Eat Peanut Chutney

“…The activation energy values for glass bottles were found to be 18.709, 10.323, 13.420, 10.422 KJ/mol for pH, carbohydrate, protein and fat, respectively and for aluminum foil 6.826, 9.162, 12.4177 and 9.41KJ/mol for pH, carbohydrate, protein and fat, respectively. Tosun 15 reported the activation energy for quality parameters and Bunkar et al, 13 has also reported similar kind of results in his work. Similarly, the temperature coefficient value of pH, carbohydrate, protein and fat is 1.3, 1.15, 1.21, and 1.14 for glass bottle, respectively and 1.1, 1.14, 1.19 and 1.16 for aluminum foil, respectively.…”

“…The lower the reaction rate constant, lesser the degradation rate and vice versa. Martins et al, 23 and Tosun 15 has reported the rate constants for quality parameters. Graph was plotted between plotted between ln (k) vs 1/T and illustrated in the Figures 10-13.…”

“…13 Oliveira et al, 14 developed shelf-life kinetic model for modified atmosphere packaging of fresh sliced mushrooms. The color change and 5-hydroxymethyl furfural formation in zile pekmezi during storage was studied by Tosun 15 and also evaluated the reaction orders, rate constants and activation energy. Kinetic model was established to explain temperature dependence of ascorbic acid loss.…”

Physical–chemical and sensory properties of pulsed electric field and high hydrostatic pressure treated citrus juices

“…The colour plays important role in the appearance and acceptability of foods (Tosun, 2004). Investigating the results of colour analysis the following can be established.…”

Sucrose in the Concentrated Solution or the Supercooled “State”: A Review of Caramelisation Reactions and Physical Behaviour

“…Colour changes together with HMF content have been studied for numerous food systems, such as fruit juices and purees [19,30,50,61,66,103,129], dairy products [27,71,86], baked goods [98,99], infant foods [46,53,101], honey [127] and model Maillard systems [28,29,118].…”